Relating energy demand
Should any unforeseen event occur which causes
unexpected excess energy consumption, the plot
for that month (or week) will fall further above the
target characteristic than usual.
to degree days
Look at the illustrated example.
For a degree-day value of a, the 'correct'
or expected ration of energy was b but
the actual quantity is was c.
The extent of the deviation (c-b) is a measure of the
unnaccountable lost energy.
Knowing the price per extra unit, you can evaluate the
cash cost of the deviation and decide what if
anything to do about it.